Purpose: The Words of Oral Reading and Language Development (WORLD) is a shared book reading intervention previously developed, piloted, and refined through an IES Development grant. This intervention is designed to develop and accelerate science and social studies content-related vocabulary and background knowledge in preschool-aged children for later reading with comprehension. WORLD incorporates explicit and implicit shared book-reading strategies (e.g., prompting, elaborating, inferencing) in rich books contexts. These strategies are intended to build sustained word and domain knowledge in young children. Through a scaffolded delivery design, lessons begin with highly specified language and progress to less specific instructional dialogue. This scaffolding is designed to facilitate independent generalization and use of the strategies among teachers. The research team will conduct a randomized study to evaluate the impact of the WORLD intervention on school readiness outcomes for children enrolled in public prekindergarten and Head Start preschool programs.

Project Activities: In each of the initial 3 years of the project, a new cohort of 60 preschool classes will participate in the study. Participating schools will include high concentrations of low socioeconomic status and ethnically and linguistically diverse students. For each cohort, a randomized cluster design will be used, with classes being assigned to implement WORLD or to a comparison condition. Researchers will first compare the WORLD intervention to business-as-usual, and then compare WORLD to more robust comparisons that will allow them to identify particular features of the intervention that are associated with effects. The three cohorts of children will be followed into early elementary school.

Products: The products of this project will be evidence of the efficacy of the WORLD shared book reading curriculum intervention. Peer-reviewed publications will also be produced.

Structured Abstract

Setting: This study will take place in four demographically similar school districts and one Head Start consortium located in southern Texas.

Population: Participants include approximately 500 preschool classrooms with a potential pool of over 5,000 preschoolers who would be eligible to participate. Demographically, over 90 percent of the preschoolers qualify for free and reduced lunch, over 50 percent are Hispanic/Latino, and over 35 percent are considered English language learners.

Intervention:WORLD is a fully developed, interactive, shared book-reading intervention designed to develop and accelerate vocabulary and background knowledge for young children with restricted vocabularies. The WORLD intervention was developed and pilot tested through a previous IES Development grant. WORLD is organized around science and social studies themes. Four themes serve as the content foci of the 18-week intervention with daily 20-minute lessons designed for each theme in 5-day instructional cycles. The themes include two science themes (Nature and Living Things), and two social studies themes (Places Where We Live and Go and Earth-Land and Water). The daily lessons are based on the themes, a selection of books, and targeted vocabulary words. Over a 5-day instructional cycle: (a) the teacher will introduce new words and concepts during a book reading session (days 1 and 3); (b) review previously taught knowledge and reread the book (days 2 and 4); and (c) integrate new words and science and social studies concepts across two books in a cumulative review of the new vocabulary words and content.

Research Design and Methods: Each year, a new cohort of 60 preschool classes will participate in the study. In each cohort, a randomized cluster design will be used, with class being the unit of randomization. Teachers in the treatment group will receive training and support to implement the WORLD intervention. In Year 1 of the study, the research team will compare the WORLD intervention to a business-as-usual (BAU) control group. The WORLD intervention is intended to improve receptive and expressive vocabulary performance of individual students, so these are the variables that will be measured for each student. In Year 2, the researchers will compare the WORLD intervention to a comparison group in which instruction is delivered using BAU techniques, but the teachers receive copies of the books used in the WORLD intervention. The research team will also follow the Year 1 sample of children into kindergarten. In Year 3, the research team will compare the WORLD intervention to a comparison group in which instruction is delivered using BAU, and teachers in the BAU group are asked to implement the WORLD Explicit Vocabulary Instruction components only. The research team will follow the Year 1 sample of children into spring of first grade and follow the Year 2 sample into kindergarten. In Year 4 of the study, the research team will follow each cohort of children into elementary school and collect school records data.

Control Condition: The WORLD intervention will be contrasted to business-as-usual and robust comparison conditions.

Key Measures: Over the course of each project year, a battery of standardized, norm-referenced, and researcher-developed measures will be used to assess language, behavior, and classroom climate. For example, the Expressive One-Word Picture Vocabulary Test (EOWPVT) is a standardized measure that will be used to assess a child's expressive vocabulary by requesting the child to name objects, actions, and concepts pictured in illustrations. To assess concept knowledge, researchers will use the Conceptual Thinking subtest of the Kaufman Assessment Battery for Children-2nd Edition. In addition, teachers will be asked to report on children's attention skills and behavior. A classroom observation system will also be used, along with a teacher-child engagement coding system. Parents will complete a family demographic survey. The research team will also collect fidelity of implementation data at three time points during Years 1–3 of the study.

Data Analytic Strategy: Multilevel modeling will be used in order to take the clustered nature of the data (students nested within classrooms) into account. These models will allow for both classroom level variables (e.g., teacher's years of experience) and student-level variables (e.g., age) to be taken into account. The data analysis will be performed separately for each year of the study, as each year involves a comparison of WORLD against a different comparison group.